The GOP presidential nominee has made claims of vote rigging over the past month.

A Donald Trump supporter who was charged with voting twice reportedly claims she did so because she feared the election was rigged in favour of Democrat Hillary Clinton.

Terri Lynn Rote, 55, from Des Moines in Iowa, was arrested on a first-degree election misconduct charge after being accused of casting one ballot at a post office, and another at a county satellite voting location.

Rote, who posted $5000 bail and was released from the Polk County Jail on Friday (28 October), a day after her arrest, allegedly said she was scared her first vote for Trump would be changed for a vote for Clinton.

Rote, who faces five years in prison if convicted of the charges, also told the radio station: "The polls are rigged."

Polk County Attorney John Sarcone said that instances of voter fraud in the state were rare, adding: "I think in the 25-plus years that I've been doing this job, this maybe the third [time] we've had some irregularity that's resulted in a criminal charge.

"People aren't voting more than once. And if they do, or attempt to do it, they will get caught because there are safeguards in place.... We want everybody to exercise their right to vote, but only once."

The allegations against Rote come following repeated allegations of vote rigging and vote flipping by the GOP nominee, which have been criticised by Democrats including US president Barack Obama, who described the claims as "irresponsible".

And during the final presidential debate, Trump shocked some with his comments that he may not accept the results of the 8 November election.